Air-compressor



` 3 sheets-sheen 1 J.. B. WRING.vv

AIR COMPRESSOR.

(No Model.)

3 Sheets-Sheet 2.

(No Model.)

J. B.WARING. AIR c'oMPRBssoR.

. Patented Aug. 1-5?, 1882.

(No Model.) 3 sneetssheet 3.

J. B. WARING.

. AIR COMPRESSOR.

Patented Aug. 15.

N. PETtRS. Pneu UNITED STAT-es `P1-ATENT OFFICE.

JOHN B. VVARING, OF NEW YORK, N. Y., ASSIGNOR OF ONE-HALF TO MILAN O. BULLOGK, `OF CHICAGO, ILLINOIS.

AIR-COM PRESSO R.

SPECIFICATION forming part of Letters Patent `No. 262,864, dated August 15, 1882.

` Application filed January 14, 1882. (No model.)

To all lwhom it may concern: l

Be it known that I, JOHN B. WAM-NG, ofthe city and county of New York, `in the State of New York, have invented certain new and usefulImprovemcntsin Air-Gompressors,oi' which the following is a specification.

In air-compressors as usually constructed, in which air is drawn into the cylinder by one stroke of a piston and expelled therefrom into the reservoiror receiver by the return-stroke ofthe piston, much difficulty is experienced inl working the compressors, owing to the variable resistance offered to the air-piston. The resistance to the movement of the piston at the beginning of the stroke, without considering friction, is nothing, while at the end of the stroke the resistance is greatest, and consequently an engine of sufficient power to overcome the terminal resistance offeredto the airpiston would have a large surplus of power at the beginning of the stroke of said air-piston.

An important object of my invention is to produce a compressor in which the resistance offered tojthe movement of the piston shall be as nearly as possible uniform during the whole length of its stroke.

To this end niyinvention consists in the combination, in an air-compressor, of two cylinders of unequal diameter arranged in line, two pistons connected together and fitting said cylinders, suction-valves for admitting air t0 the larger cylinder upon the inner side of its piston, valves fdr passing air therefrom to the smaller cylinder'upon the outer side of the smaller piston, a discharge valve or valves for said smaller cylinder, preferably arranged in A its piston, and preferably also a pipe or conduit for admitting compressed air for acting upon the inner side of said smaller piston. The two pistons may be connected by means of a hollow trunk, which receives within it a stationary discharge-pipe fitted with a pistonhead, and through which air passes to the-rescrvoir or receiver.

The invention also consists in the combination, with the two cylinders, their connected pistons and valves, of a reservoir or receiver which surrounds the smaller cylinder,and into which the partly-compressed air is discharged from-the larger cylinder and thence delivered into the smaller cylinder for further compression.

The invention also consists in the combination, with the two cylinders, their connected pistons, and the reservoir or receiver surrounding the smaller cylinder, of water-jackets surrounding said smaller cylinder and said reservoir or receiver,whereby the partly-compressed air contained in the reservoir and containing a large amount of heat is subjected to the action of both water-jackets. `The larger cylinder is also preferably provided with a waterjacket, and I provide pipes or passages for supplying water to the jacket of the reservoir or receiver, thence to the jacket of the smaller cylinder, and finally through and out of the jacket of the larger cylinder.

The invention also consists in details ofconstruction to be hereinafter explained.

In the accompanyingdrawings,Figure lrepresents a longitudinal irregular section of a compressor embodying myinvention upon the dotted -line y y, Fig. 2. Fig. 2 represents a transverse section thereof-upon the dotted line a: x, Fig. l; and Fig. 3 represents an end view of the compressor, looking from the left toward the right, certain parts in Figs. 2 and 3 being -removed to better illustrate the invention.

Similar letters of reference designate corresponding parts in all the figures.

A B designate respectively cylinders which are arranged-in line and are of unequal diameter, the cylinderA in the present instance being double the diameter of the cylinder B. As here represented, the two cylinders are comprised in a single casting, and arcseparated by a common head, C, cast in one with the cylinders, as shown,or made separate from them,if desired.

' D E designate respectively pistons,one of which, D, is fitted tothe larger cylinder, A, while the other, E, is fitted to the smaller cylinder, B. The two pistons are rigidly connected,so that they move backward and forward in unison, and in the present example of my invention they are connected by a hollow trunk, F, formed in one casting with the piston D, and of a size to tit snugly within` the smaller cylinder, B. The end of the trunk F .is open, and the piston E is secured thereto by IOC) means of a stud-bolt, a, fixed in the trunk, and

circular jam-nuts b b, having notches in their faces forturnin g them upon the said bolt. The packing of the piston E is effected by two leather-cup packings, c c, which are clamped between the meeting faces of the piston E and the end of the trunk F. The piston D, as here shown, is packed tight by means of leathercup packings d, a metal ring, d', located between them, and a gland or packing-ring, d?, which may be clamped and held on the piston by bolts d3 to compress and tighten the packing.

'Ihe mechanism for operating the pistons D der and piston are made longer than is absolutely necessary, so as to have a long bearing. In order to obtain such long bearing without unduly increasing the length of the compressor, the endof the cylinder A has in it slots or recesses A', into which the cross-head or piece Gr moves as the pistons are moved-forward.

Il designates a reservoir or'receiver, into which partly-compressed air is discharged from the cylinder A, and from which such air passes to the cylinder B to be nally compressed. This reservoir or receiver preferably surrounds and incloses the smaller cylinder, B, as here represented. As clearly shown, the common head G projects considerably beyond the cylinder A, and I connect the reservoir or receiver H and the common head by means of bolts f, hinged or pivoted at f to one part-in this instance the reservoir or receiver H-and fitting in slots or notches f2 in the other partin this instance the common head C. By loosening the nuts of the bolts f all the bolts may be swung outward upon their pivots sufciently to disengage them from the slots or notches f2 to permit of the detachment of the reservoir or receiver.

In order to prevent leakage, I form in the meeting faces of the head C and reservoir or receiver H correspondingly-opposite angular grooves, and in such grooves I fit a packingring, g, one of the grooves being undercut or dovetailed, so as to retain the packing when the parts are separated.

The suction-valves for admitting air to the larger cylinder, A, upon the inner side of thepiston D and the valves for discharging air partially compressed in the cylinder Aiuto the reservoir or receiver H may be of any desirable construction; but I prefer to use a novel arrangement of valves, which I will now describe.

- The suction-valves h, for admitting air into the cylinder A, are composed of segmental strips of rubber or similarexible material, and they are held in place by segmental pieces t', which are secured by bolts t" to the head C, and constitute the valve-seats, the form of both valves and seats being clearly shown in Fig. 3, one side of said drawing showing the v alve and seat in place, and the other side showing the valve and seat removed and the outline of a facing-piece, i2, upon which the valve-seats and valves are bolted. The valve-seats i lit around the outside of the cylinder A, and are provided with agreat number of openings, t3, through which air is drawn, and which are closed by the valves h. Between the head C and thevalve-seats i are formed segmental cavities or recesses j, which give room to allow the valves hto open inward when the piston D moves back or outward, and the said recesses or cavities communicate with the cylinder A by a number of radial ports,j.

The discharge-valves lc of the large cylinder A, through which the partially-compressed air enters the reservoir or receiver H, are composed of segmental strips of rubber or other suitable material similar to the valves h, and the form of which is shown in Fig. 2. The disch arge-valves 7s are secured to the seat upon the opposite side of the head() from the valves h, and close a large number of openings, 7c', in said seat, which communicate with the radial ports j', through which air both enters and leaves the cylinder A. The valves k are held in place by segmental guards k2, secured to the head (l by bolts k3, and the form of 'both valves and guards is shown clearly in Fig. 2, the lefthand side of which shows the guard and valve in place, while the right-hand side shows the guard and valve removed and a full view of the several openings, 7c', in the valve-seat.

The valves whereby air is admitted from the reservoir or receiverH to the cylinder B upon the outside of the piston E may be of any suitable form but a very desirable construction is here shown, which I will now describe.

'lhe head B ofthe cylinder B is secured thereto by bolts l, and forms the valve-seat, it being provided with openings l for the passage of air. v

The valve I, which is composed ot' an annular ring or disk of india-rubber, leather, or other suitable material, closes the openin gs l', and is held in place by a valve-guard, I, secured in the head B by a bolt, m, and cap-nut m. In order to leave as little clearance as possible in the cylinder B,'the valve-guard I is constructed with a circular cavity, 'm2, which receives the jam-nuts b b, whereby the piston E is secured to the trunk F, and in order to save space the guard I itself ts in a recess or cavity, l2, of corresponding form in the head B.

The discharge-valve, which controls the discharge of air from the cylinder B, is composed of an annular corrugated disk or diaphragm, J, which covers openings n in the piston E, and is secured in place by an annular nut, a', screwed into thepiston E. The air, after pass- IOO IOS

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ing the valve J, enters the trunk F, which co'nnects the pistons D and E.

K designates a pipe or conduit, of which only a portion is shown. At its end, which tits within the trunk F, it is provided with a leather-cup packing, o, a metal ring, o', and a gland or. cap, K', which is tightened by bolts o2, tocompress the packing. The pipe or conduit, K, has a surrounding jacket, which provides for water-circulation to cool the air, and may be provided with suitable inlet and outlet pipes. (Not here shown.) The outer end of said pipe or conduit K (not here shown) abuts against or is ixed to a suitable support, whereby it is held stationary, and the air may be conducted from it by a branch pipe toa reservoir or receiver, in which the compressed air is stored for use.

\ I will now describe the means whereby the various parts ot' the compressor are kept cool for cooling the compressed air.

The reservoir or receiver H is composed of -two parts or outer and inner shells, p p', se;

cured together by abolt, p3, leaving between` them a space or jacket, p2, at the sides and end. Upon one or the other of the shellsin this instance on the inner shell-is formed a spiral rib, g, at the end and a second spiral r-ib, q', running round the jacket from the closed end toward the common head O. The cooling-water enters through a supply-pipe, r, and passes through a passage or duct, r', which delivers it at the center of` the jacket p2, near the end of the reservoir or receiver H, from whence it passes outward in a spiral direction, following the convolutions of the spiral rib q, and thence along the body ofthe reservoir or reeeiver,followiu g the convolu tions of the spiral rib q until it reaches the end thereof, where it enters a passage ordnet, r2. The smaller cylinder, B, has a removable lining held in place by the head B', which forms a water-jacket, s, and-which has upon its exterior two spiral ribs,s, forming a double thread. 'Vlhe water, entering the jacket s through' the passage or duct lr2, passes toward the closed end of the cylinder B through the jacket, following the convolutions ot' one thread and then returns, followingthe convolutions of the other thread,

and enters a passage or duct, r3, in the com` mon head G. (Shown in dotted outliuein Fig.

1.) Thelarger cylinder, A, is constructed with a jacket, A2, and the water passes from the passage or duct r3 through this jacket, and thence out of a discharge-pipe, r4.

In compressing air the ,h'rst compression, which is elfected in the cylinder A, generates a very large amount of heat, and as the reservoir or receiver H is much larger than the smaller cylinder, B-say seven times largerthe partially-compressed air passes slowly` through the reservoir or receiver H, and is subjected to the action of the coldest water passing through .the jacket of the reservoir or receiver H,`and the water passingthrough the jacket of the smaller cylinder, B, and hence is greatly reduced in temperature before it enters the cylinder B. i

Turning,'now, to the operation of my compressor, we will suppose that both pistons are moving toward the left. The airis drawn in through the suction-valves h of the larger cylinder to hll the space between the inner side of the piston D and the end ot' the cylinder, while at the same time the air is drawn from the reservoir or receiver H through the suction-valve I of the smaller cylinder to fill said cylinder. On the return-stroke the air in theV larger cylinder is forced through the valves 7c into the reservoir or receiver H, while the air in the smaller cylinder is forced through the vvalve J into the trunk F and pipe or conduit ythereby augmented. Considering, now, the

resistance offered to the movements of the pistons D and E, it will be readily understood that when the said pistons are moving toward the left the piston D will have no resistance save that due to friction, while the piston E will be resisted by the pressure of air in the reservoir in which the compressed air is stored, which may be supposed to be seventy-live pounds per square inch. Thepiston E has, however, the pressure of the partially-compressed air upon its opposite or right-hand side, which may be supposed to be thirty-live pounds per square inch, and hence the piston `is balanced to that extent, and the unbalanced resistance offered by the air to the movement of both pistons will be only about forty pounds per square irich on the area of the piston E. In -moving toward the right the initial resistance o'ered to the piston Dis next to nothing, while the terminal resistance is thirty-tive pounds, making an average of seventeen pounds per square inch. The resistanceA 0ffered to the piston E is, say, thirty-five pounds; but this is more than balanced by the pressure IOO IIO

of seventy-live pounds on4 the opposite side of said pistou, and the excess of pressure on the pistou E is opposed to the resistance on the piston D, and partially balances the same. It will therefore be seen that when moving to` ward the left the resistance at the termination of the stroke does not materially exceed the initial resistance,and that when moving toward the right the air-pressure on the piston E actually overbalances the resistance :at the beginning of the stroke, and nearly balances the resistance at the endof the stroke. The work, therefore, being so nearly uniform throughout the stroke, it will be obvious that a smaller engine could be used than when the resistance is nothing at the beginning ot' the stroke and reaches its maximum at the end of the stroke; or, what is preferable, an engine of the same size could be used, cutting off much earlier in the stroke, and therefore ef-- fecting an economy of steam by its greater expansion. i

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Although I have shown the reservoir or re. ceiver H as surrounding the smaller cylinder, B, and prefer to so arrange it, it might be differently arranged, and the construction and arrangement of the valves and other features of the compressor might be modified or changed without departing from my invention.

What I claim as my invention, and desire to secure by Letters Patent, is

1. The combination, in an air-compressor, of

two cylinders of'unequal size arranged in line, t

two pistons connected together and iittin g said cylinders, suction-valves for admitting air to the larger cylinder upon the inner side ot' its piston, valves for passing air therefrom tothe smaller cylinder upon the outer side of the smaller piston, and a discharge valve or valves for said smaller cylinder, substantially as specified.

2. The combination, in an air-compressor, of two cylinders of unequal size arranged in line, two pistons connected together and fitting said cylinders, suction-valves for admitting air .to the larger cylinder upon the inner side of its piston, valves for passing air therefrom to the smaller cylinder upon the outside of its piston, a discharge valve .or valves for said smaller cylinder, and a pipe or conduit for admitting compressed air to act upon the inner side of said smaller piston, substantially as specified.

8. The combination, in an air-compressor, ot' two cylinders of unequal size arranged in line, two pistons connected together and fitting said cylinders, suction-valves for admitting air to the larger cylinder upon the inner side of its piston, valves for passing air therefrom to the smaller cylinder upon the outer side of its .piston, and discharge-valves for said smaller piston, arranged in said piston,-and providing for the discharge of air through said piston, substantially as specified.

4. The combination,i-n an air-compressor, of

' two cylinders of unequal size arranged in line,

two pistons fitting said cylinders, a Vhollow trunk connecting said pistons and communicating with a reservoir, suction-valvesfor admitting air to the larger cylinder upon the inner side of its piston, valves for passing -air therefrom to the smaller cylinder upon the outer sideof .its piston, and discharge-valves for passing air through said smaller piston into said trunk, substantially as specified.

5. rlhe combination, in an air-compressonot two cylinders of unequal size arranged in line, two -pistons fitting said cylinders, a hollow trunk connecting said pistons, a stationary discharge-pipeittingclosely within said trunk, suction-valves for admitting air to the larger cylinder upon the inner side of said piston, valves for passing air therefrom to the smaller cylinder upon theouter side of its piston, and a discharge valve or valves for passing air through said smaller pistons into said trunk, substantially as specified.

' 6. The combination, in an air-compressor,.of two cylinders of unequal size arranged in line, two pistons connected together and fitting said cylinders, a reservoir or receiver surrounding the smaller cylinder, suction-valves for admitting air to the larger cylinder upon the inner side of its piston, valves for discharging air therefrom to the reservoir or receiver, a valve or valves whereby air passes from said receiver or reservoir to said smaller cylinder upon the outer side of its piston, and a discharge valve or Valves for said smaller cylinder, substantially as specified.

7. The combination, in an air-compressor, of two cylinders of unequal size arranged in line, two pistons connected together and fitting said cylinders, a head between said cylinders and common to both, a reservoir or receiver surrounding the smaller cylinder and secured to said common head, valves on opposite sides of said common head for admitting air to the larger cylinder upon the inner side of the piston and for discharging air therefrom into said reservoir or receiver, and Valves for admitting air from said reservoir or receiver to Vthe smaller cylinder upon the outside of its piston, and for discharging air from said smaller cylinder, substantially as specified.

8. The combination. in an air-compressor, of two cylinders of unequal size arranged in line, a water-jacket surrounding the smaller cylinder, two pistons connected together and itting said cylinders,an air reservoir or receiver surrounding said smaller cylinder, and a waterjacket surrounding said reservoir or receiver, whereby the air .in said reservoir or receiver is cooled by contact with both water-jackets, substantially as specilied.

y9. The combination, in an air-compressor, of two cylinders of unequal size arranged in line, a water-jacket around said smaller cylinder, an air-reservoir or receiver surrounding said smaller cylinder, a water-jacket around said reservoir or receiver, and pipes or passages for supplying water to the jacketof the reservoir or receiver, thence conducting said water to the jacket of said smaller cylinder, and finallydischarging the water therefrom, substantially as specified.

10. The combination,in anair-compressor, of two cylinders of unequal size arranged in line, a reservoir or receiver surrounding the smaller cylinder, water-jackets for both said cylinders and for said reservoir or receiver, and pipes or passages for supplying water to the jacket of the reservoir or receiver, and for conducting water from said jacket to the jacket of the smaller cylinder, thence to thejacket of the larger cylinder, and finally for discharging the water from the jacket of said larger cylin der, substantially as specified.

11. The combination, in an air-compressor, of the two cylinders, and the reservoir or receiver H, composed of two parts fitting one within the other, and having a spiral passage along its side or cylindricportion and its closed end, substantially as speci tied.

Witnesses:

EDWIN H. BROWN, FREDK. HAYNEs.

J. B. WARING.

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